This is what happened when we depends too much on the practical application of science without incorporating the ecological condition factor of the site.
Yeah, heavy downpour increases the water pressure within the confined retaining wall (as it is already build up due to not much pores for the liquid to enter and exit the soil. Hence, the wall collapse.
One of my favourite subject in the university was on the slope stabilization and we studied mainly on the eco-engineering/soil bio-engineering, etc of slope stabilization. It is a holistic approach in stabilizing slope by not only using engineering design but we take into account the ecological importance of maintaining the engineering structures.
Hence, we did a lot on solving the engineering problem (particularly on slope stabilization) by using the basic science approach i.e. build-up water pressure due to the concrete structure, to plant species with high-energize plant that able to photosynthesis+evoporate & able to take out say, 1kg of water in a day.
One of the species that meet the above-mentioned requirement is the Vertiver sp.
Anyway, those were the days and when i read the news just now, it reminds me of the subject i took during the course in the university. Oh, and i was furious I didn’t get 4.0 when I know i did well during the final exam, presentation, laboratory exercise AND the class test. I wonder why.